Why would reticulocyte counts be increased in chronic blood loss, but decreased in Vitamin B12 deficiency?

Answer 1

Reticulocytes increase in blood loss as a compensatory measure. Reticulocytes are immature RBCs, so their presence reflects an attempt by the bone marrow to produce more RBCs (driven by EPO -- erythropoietin).

B12 is required for DNA synthesis and cell division, so synthesis of RBCs would be impaired. In fact, with folate or B12 deficiencies, you may observe a macrocytic anemia -- few red blood cells of larger than normal size. In this situation, the RBCs can grow and produce hemoglobin, but they can't divide, so they just swell in size.

Answer 2

2/5 Americans suffer from B12 deficiency. B12 is available from meats but is improperly absorbed from the stomach in many people. Sometimes this is caused by eating heavy meals, so the B12 isn't absorbed because the body is busy breaking down fats and proteins. It can also be caused by a disruption in the healthy bacterial flora of the stomach which can be killed off through the use of antibiotics, medications, yeast infections and a few other things. Dairy is fortified with B12, so it is not naturally occurring and the body may only absorb up to 60% of the synthetic material. It doesn't hurt to take a supplement, but the first thing to go with a B12 deficiency is brain functioning. You will find you are forgetful, easily confused, moody or depressed and have very low energy. Also it depends how long you have been veg., if it's only recently this is probably not because of your diet. Maybe your fingernails look curved because of work that you do... do you type all day long, have to wear gloves all day, do a lot of gripping? Could be many reasons, but you would have some internal clues before the external clues manifested themselves, if this was a B12 deficiency.

Answer 3

Retics are immature RBCs. If blood is chronically being lost, the bone marrow is constantly putting out RBC's. The marrow cannot make the mature ones fast enough and often sends out the retics to make up for the low count.

I don't remember why it is low with B12 issues.

I saw your other blood question too. What are you studying for?

Answer 4

While apheresis collection of any blood component may be associated with a mild increase in peripheral white cell count, due to transient demargination of neutrophils, there is no sustained wbc elevation associated with the procedure.